fs.writeFile(file, data[, options], callback)

• file <string> | <Buffer> | <URL> | <integer> 文件名或文件描述符
• data <string> | <Buffer> | <TypedArray> | <DataView>
• options <Object> | <string>
  • encoding <string> | <null> 默认值: 'utf8'
  • mode <integer> 默认值: 0o666
  • flag <string> 参见 文件系统 flags 支持。默认值： 'w'。
  • flush <boolean> 如果所有数据成功写入文件，并且 flush 为 true，将使用 fs.fsync() 刷新数据。 默认值： false。
  • signal <AbortSignal> 允许中止正在进行的 writeFile 操作
• callback <Function>
  • err <Error> | <AggregateError>

当 file 是文件名时，会异步将数据写入该文件，如果文件已存在则会替换它。data 可以是字符串或缓冲区。

🌐 When file is a filename, asynchronously writes data to the file, replacing the file if it already exists. data can be a string or a buffer.

当 file 是一个文件描述符时，其行为类似于直接调用 fs.write()（这是推荐的做法）。有关使用文件描述符的说明，请参见下面的备注。

🌐 When file is a file descriptor, the behavior is similar to calling fs.write() directly (which is recommended). See the notes below on using a file descriptor.

如果 data 是缓冲区，则会忽略 encoding 选项。

🌐 The encoding option is ignored if data is a buffer.

mode 选项只会影响新创建的文件。详情请参见 fs.open()。

🌐 The mode option only affects the newly created file. See fs.open() for more details.

import { writeFile } from 'node:fs';
import { Buffer } from 'node:buffer';

const data = new Uint8Array(Buffer.from('Hello Node.js'));
writeFile('message.txt', data, (err) => {
  if (err) throw err;
  console.log('The file has been saved!');
}); 拷贝

如果 options 是字符串，则它指定了编码方式：

🌐 If options is a string, then it specifies the encoding:

import { writeFile } from 'node:fs';

writeFile('message.txt', 'Hello Node.js', 'utf8', callback); 拷贝

在未等待回调的情况下多次使用 fs.writeFile() 写入同一个文件是不安全的。对于这种情况，推荐使用 fs.createWriteStream()。

🌐 It is unsafe to use fs.writeFile() multiple times on the same file without waiting for the callback. For this scenario, fs.createWriteStream() is recommended.

与 fs.readFile 类似，fs.writeFile 是一个便捷方法，它在内部执行多次 write 调用以写入传入的缓冲区。对于对性能敏感的代码，建议考虑使用 fs.createWriteStream()。

🌐 Similarly to fs.readFile - fs.writeFile is a convenience method that performs multiple write calls internally to write the buffer passed to it. For performance sensitive code consider using fs.createWriteStream().

可以使用 <AbortSignal> 来取消 fs.writeFile()。取消是“尽力而为”的，因此仍有可能写入部分数据。

🌐 It is possible to use an <AbortSignal> to cancel an fs.writeFile(). Cancelation is "best effort", and some amount of data is likely still to be written.

import { writeFile } from 'node:fs';
import { Buffer } from 'node:buffer';

const controller = new AbortController();
const { signal } = controller;
const data = new Uint8Array(Buffer.from('Hello Node.js'));
writeFile('message.txt', data, { signal }, (err) => {
  // When a request is aborted - the callback is called with an AbortError
});
// When the request should be aborted
controller.abort(); 拷贝

中止正在进行的请求并不会中止单个操作系统请求，而是中止 fs.writeFile 执行的内部缓冲操作。

🌐 Aborting an ongoing request does not abort individual operating system requests but rather the internal buffering fs.writeFile performs.